A spokesperson said: “Half a million pounds might be small change to councils, but to hard-pressed drivers, every penny counts. Many will think they are being made to pay a penalty for doing the right thing and buying a ticket.”

In total, 50 councils were asked to provide information on their earnings from parking machines that do not give change.

But 21 could not supply the figures, while three said they did not use pay-and-display machines.

Peterborough City Council said that it had been able to keep parking tariffs low by using ticket machines that do not give change, which are cheaper to purchase and maintain than those that do give change.

But several councils employ a “linear tariff” system that gives motorists extra parking time for any additional money they pay into machines.